I've read from various reliable sources about why not use 0W-30 oil instead of the 5W-30 or 10W-30. I've read hundreds of opinions on the matter and none seemed address the issue. This is the rationale. That most of the engine wear occurs at start up whereby because of temporary tight tolerances the friction surfaces need the lubrication immediately. Thus at 0W, the oil is thinner and more of the oil will get to the tighter friction area for lubrication. Further when warmed up the engine normally operates at the around the same temperature (200-215F) whether idling or at freeway speed. Meaning that the upper digits of the viscosity index whether it be 20,30 or 40, the oil will provide sufficient lubricating features for protection UNLESS for some reason the engine overheats. My '99 Ford Ranger 4.0L has around 167K miles. Ive always used 5W-30 but am thinking of switching to 0W-30 if it would help preserve the life of my engine which I'm starting to hear slight clickety-clack noise from the engine. Is this a prudent move? How about shifting to a synthetic oil, is it worth the money?

 

Synthetic is usually less than a five dollar difference. If you live somewhere where 0w30 is optimal due to cold mornings, I would use it, and by cold, I mean in single digits or below. The noise may get worse as the engine het older due to wear and using synthetic oil. Here's the thing, I bought my 94 Xlt off the Ford dealer new. For over a decade used almost every brand off the shelf in weights from 0w30, 5w30, 10w30, 10w40, 0w40 in dino and synthetic and blends. Never once did it hurt the inside of the engine. Alas at 231000 miles, I got tboned and flipped. That's what killed it. Try not to overthink of, use what your owners manual calls for and sleep well knowing it will rust out before the engine locks up due to oil failure. Keep the oil change schedule to what your owners manual states and you'll be fine. The 0w5w10w is relative to the outside temperature as well. Quitest mine ever ran was on Mobil 1 0w40. She purred in a cold winter using it. Good luck and kudos, by your post your already more educated than the average consumer on proper care for your vehicle. And yes I would use synthetic for all the reasons you listed. Better high heat protection cleaning ability and flow characteristics compared to dino or blends. And toss in some lubri moly mos2 as well if you love your truck.

 

5w30 oil is for temperatures from +5 degrees celcius to - 15 degrees celcius

0w30 oil is for temperatures from - 16 degrees celcius to - 25 degrees celcius

0w20 oil is for temperatures from - 26 degrees celcius to - 45 degrees celcius

 

You have several recent topics that go into a deep analysis of motor oil.

If start-up is the concern, (and that's a good focus), then chose a 0W oil that is FULLY synthetic.

There is really only one "FULLY synthetic oil" readily available in the USA at a decent price and that is 0W-40 Euro Formula by Mobil 1.

But that is already stated in recent posts.

So what is the concern at start-up if "0W" applies to start up situations?

 

cold temperature flowability , the thicker the oil in cold climates the longer it takes to be forced to critical internal moving parts

10w 30 is fine for warm climates , not so good for colder climates

 

I thnk I use 5W30 and I probably suffer the coldest starts of anyone haha. But I have a built in oil pan heater (and like 3 other "something heaters")

 

Mobil 1 0W-40 Euro is the thinnest oil on the market at 0 Fahrenheit.

At -20 degrees it is thinner than M1 0W-20 or M1 0W-30 with Redline 5W-20 being thinner.

This measured as a pump-ability index for the oil. (How freely does the oil move through the system at various temps.

So you wonder how a 0W-40 can be thinner than a 0W-20?

The answer lies in the base oil used and there you have 5 grades:

Grades of oil.

Motor oils are derived from base stocks. That is, a generic oil base is modified with additives to produce a lubricant with the desired properties. A base stock oil with no additives would not perform very well at all. Base stocks are classified by the American Petroleum Institute (API) and fall into one of five categories.

•Group I and II - these are mineral oils derived from crude oil

•Group III - this is a highly refined mineral oil made through a process called hydrocracking. In North America this group is considered a synthetic oil, for marketing purposes.

•Group IV - these are true synthetic oils, known as Polyalphaolefin (PAO).

•Group V - these are synthetic stocks other than PAO's and include esters and other compounds.

Mobil 1 0w-40 Euro is a grade IV oil unlike 99% of the US branded oils. I believe Amsoil makes a Grade IV and that's the only other one I ma aware of.

So 99% of all "synthetic oils" are actually not synthetic but based on Grade III std's as used in the USA.

-------------------------

But keep this in mind, that older oil and varnish lined internal engine components dramatically affect flow ability at low temps.

So I recommend that as you enter into October that you use a product like BG Engine Purge just before changing your old oil. That will clean the internal components and remove a lot of built-up varnish which will increase flow ability.

Then change your oil using a 0W grade. Look for a Grade IV PAO oil. Walmart carries M1 0W-40 for cheap.

 

Excellent discussion on Group IV vs Group III oil:

Group IV starts at 5:00 and Group III starts at 1:35


That is why Mobil 0W-40 Euro (group IV, PAO) is such an awesome buy.

 

Use what FORD calls out !

I run the 5-20 all the time here in the north east, when I get to SoCal I will check around for what oil is called for out there, thinking the same stuff but maybe a little heavier.

 

I'm a big OEM guy but not when it comes to oil.

5W-20 is spec'd in order to meet MPG requirements set forth by the Fed Gov't. Also, it's much cheaper than a full synthetic motor oil of Group IV. If you do a lot of driving in the South, a 0W-40 will offer far greater protection in high heat situations and at least, with Mobil 1 0w-40, be thinner on cold startups than Ford's 5W-20.

So you WILL have much greater engine protection from the Mobil 1 product but you might lose a tiny bit of MPG's, although the opposite could very well be true since it is a fully engineered product that has same shaped molecules vs Ford's C III mineral oil based product.

All in all, it is far superior protection and costs less than $5 a quart.